Question

Joseph took some sodium hydroxide solution in a dish and dipped a red litmus paper into it . the red litmus turn blue. He poured vinegar in the same solution and dipped blue litmus paper . it did not turn red.(vinegar, being an acid, must turn blue to red) what may be reason.

Answer 1

NaOh+Ch3CooH -> Ch3CooNa +H2O

Before adding acetic acid it turns red to blue . After adding acetic acid colour of pH will remain same.

Since now the solution is neutral.

Vinegar-(contain Acetic Acid).